Marking is performed on a tire which has been subjected to a performance test using a tire testing machine. In this marking process, a heated marking pin presses a marking tape against the tire, so that a desired mark is printed on the tire by a thermal transfer method.
Patent Document 1 discloses a marking device which disposes two adjacent tapes in a substantially circumferential direction (tangential direction) of a tire and assigns a separate marking pin to each of the two tapes so as to print two marks on the tire. In the marking device, the marks may be printed in different colors by causing the two tapes to have different colors.
However, it is difficult to use the marking device of Patent Document 1 for a case where a printable area on the surface of the tire is small because the two printing positions on the surface of the tire are different from each other in the circumferential direction. In addition, in a case where the marking is performed at the same positions of the same types of tires while switching the tapes in use, the position of the tire needs to be adjusted such that the printing position is positioned directly below the tape in use. For this reason, there is a need to perform control that adjusts a rotation stop position of a spindle or a rotation angle of the marking pin with respect to the tire in every tape in use.
Meanwhile, Patent Document 2 discloses a marking device which disposes two tapes in series in the radial direction of the tire. According to the configuration, when the marking is performed at the same positions of the same types of tires while switching the tapes in use, there is no need to adjust the position of the tire in the circumferential direction.
However, since a separate marking pin is assigned to each of two tapes, additional mechanisms (a driving mechanism, a temperature adjusting mechanism, and the like) are necessary for each marking pin, so that the marking device of Patent Document 2 has demerits in the complexity of the device and the production cost of the device. Furthermore, when the marking is performed on the same positions of the same types of tires while switching the tapes in use, there is a need to adjust the position of the tire in the radial direction such that the printing position is positioned directly below the tape in use. For this reason, there is a need to perform control which adjusts the tire stop position by a conveyor or the stop position of the marking device in the radial direction of the tire whenever switching